Childhood Cardiac Tumors - Types, Diagnosis, and Treatment

Introduction

Childhood cardiac tumors are uncommon tumors that can be benign (noncancerous) or sometimes malignant (cancerous). These tumors may arise primarily from the muscle layer, inner lining, or the surrounding outer muscle layer of the heart. It can be either primary or secondary. Primary childhood cardiac tumors are tumors that arise from the heart, whereas secondary cardiac tumors refer to tumors that occur due to cancer spread from other organs. Primary childhood cardiac tumors are rare than secondary tumors, with a prevalence of 0.0017 to 0.28 percent.

Most primary childhood cardiac tumors are benign, whereas malignant primary cardiac tumors account for only 10 percent of children. Secondary malignant cardiac tumors are 10 to 20 times more common in children than primary malignant tumors. Tumor biopsy remains the gold standard for a definitive diagnosis of childhood cardiac tumors. Non-invasive diagnostic tools used for childhood cardiac tumor diagnosis include CT (computed tomography), echocardiography, and MRI (magnetic resonance imaging). Surgical resection is the mainstay treatment for symptomatic, benign non-myxomatous childhood cardiac tumors. Other treatment options include chemotherapy, radiation therapy, or targeted therapy. Early diagnosis and treatment can help improve the prognosis and overall survival of children with cardiac tumors.

What Are the Different Types of Childhood Cardiac Tumors?

Childhood cardiac tumors can be either benign or malignant. Benign childhood cardiac tumors are more common than malignant cardiac tumors in children.

Benign Childhood Cardiac Tumors:

The benign childhood cardiac tumors include:

• Rhabdomyoma: Rhabdomyoma is the most common childhood cardiac tumor arising from the heart's striated muscles. It constitutes more than 60 percent of all primary cardiac tumors in children. It is most commonly caused by genetic changes that occur during the gestation period. It is located more commonly in the heart’s ventricles but may also be seen involving the auricles of the heart.

• Myxoma: Myxomas are rare childhood cardiac tumors and are most commonly seen in adults. It accounts for only nine to 15 percent of all childhood cardiac tumors. It is often associated with an inherited condition called the Carney complex.

• Teratoma: Teratoma is the second most common childhood cardiac tumor after rhabdomyoma. It is most commonly seen in the heart’s pericardial cavity. It is mostly benign, but some teratomas may be malignant.

• Fibroma: Fibroma is a benign, primary childhood cardiac tumor that most commonly occurs in children who are under one year of age. It comprises connective tissues and fibroblasts. It is also most commonly observed in the heart’s ventricles. The left ventricle is the most common site for cardiac fibroma, seen in nearly 57 percent of cardiac fibroma cases, followed by the right ventricle in 27.5 percent of all cardiac fibroma cases.

• Hemangioma: Hemangioma is an extremely rare childhood cardiac tumor that can develop anywhere within the cardiac muscle layers. The clinical outcomes of hemangioma in children are unfavorable due to bleeding from ruptured blood vessels, high cardiac output, cardiac failure, and thrombocytopenia (low platelet level).

• Histiocytoid Cardiomyopathy Tumor: Histioid cardiomyopathy tumor is a rare, benign, inherited cardiac tumor in children. It develops in the heart cells that regulate the heart rhythm. It is also called a Purkinje cell tumor. Common clinical presentations include ventricular tachycardia, premature ventricular contractions, and partial or complete atrioventricular block.

• Lipoma: Cardiac lipoma is a rare, benign tumor in children that accounts for less than five percent of all childhood cardiac tumors. Arrhythmias and atrioventricular block are the most common symptoms of childhood cardiac tumors.

Malignant Childhood Cardiac Tumors:

Primary malignant cardiac tumors are rare than secondary malignant cardiac tumors that occur in children.

• Angiosarcoma: Angiosarcoma is the most common primary malignant cardiac tumor in children. It most commonly develops in the right auricle or pericardium of the heart. The prognosis is poor, and in most cases, patients die quickly after the onset of symptoms.

• Rhabdomyosarcoma: Rhabdomyosarcomas are the second most common primary malignant childhood cardiac tumor that originates from the striated muscle of the heart. Common clinical presentations include fever, weight loss, malaise, and anorexia. In contrast to angiosarcoma, rhabdomyosarcoma does not show any diffuse pericardial involvement.

• Fibrosarcoma: Fibrosarcomas are benign, mesenchymal childhood cardiac tumors of fibroblastic origin. It can be seen within the right or left heart chambers. It constitutes three percent of all malignant cardiac tumors. The prognosis is often poor, with death ensuing within one year of diagnosis.

Other common primary malignant cardiac tumors in children include leiomyosarcoma, chondrosarcoma, undifferentiated pleomorphic sarcoma, lymphoma, and synovial sarcoma. Secondary malignant cardiac tumors in children include sarcoma, melanoma, and leukemia. These tumors start in other body parts and spread to the heart. It has poor prognosis than primary malignant tumors and requires aggressive treatments to improve the prognosis.

What Are the Symptoms of Childhood Cardiac Tumors?

The symptoms may vary with the type and severity of childhood cardiac tumors. The signs and symptoms of a cardiac tumor include;

• Abnormal heart rhythm.

• Difficulty breathing, especially when the child is lying down.

• Tightness or pain in the chest that gets better when the child is sitting up.

• Persistent cough.

• Fast heart rate.

• Dizziness.

• Fatigue.

• Swelling in the legs, abdomen, or ankles.

• Weakness or numbness in the arms, legs, or face.

• Loss of coordination and balance.

How Are Childhood Cardiac Tumors Diagnosed?

The diagnostic measures for childhood cardiac tumors include;

• Physical Examination: The doctor will primarily perform a physical examination to look for signs and symptoms of the condition, such as a lump on the chest or anything that seems unusual. They might also ask the parents about the child’s medical history to find out the underlying cause of the condition.

• Imaging Tests: Imaging tests like chest X-ray, MRI (magnetic resonance imaging), CT (computed tomography) scan, and echocardiogram provide detailed images of the heart and its internal structures. It helps determine the size, location, and extent of the tumor. It also helps in determining the stages of the malignant childhood cardiac tumor.

• Cardiac Catheterization: Cardiac catheterization is a diagnostic procedure that looks for abnormal areas or cancer inside the blood vessels and the heart. It is an invasive procedure in which a long, thin, flexible tube is inserted into the blood vessels in the arm or groin and then into the coronary arteries that supply blood to the heart. A contrast agent is then injected into the catheter. Live digital images are created as the contrast material moves through the heart's chambers, blood vessels, and valves. The live images created will help detect any blockage in the coronary artery and evaluate the heart's normal functioning.

• Biopsy: Doctors recommend a biopsy to have a definitive diagnosis of the condition. It helps distinguish between benign or malignant childhood cardiac tumors. In a biopsy, a small tissue sample is removed from the tumor using a needle, and the removed tissue sample is taken to the laboratory for pathological examination.

What Are the Treatment Options for Childhood Cardiac Tumors?

The treatment planning for childhood cardiac tumors is planned by a medical team involving a pediatric cardiologist, radiation oncologist, pediatric heart surgeon, and child-life specialist. The treatment options include;

• Chemotherapy: Chemotherapy uses drugs to kill cancer cells. It can be given in the form of pills or injected into a muscle or vein.

• Surgery: Surgery is a mainstay treatment for benign, symptomatic childhood cardiac tumors. However, it is not indicated mostly in malignant tumors as it may induce recurrence. Surgery for primary childhood cardiac tumors has good and long-term outcomes with a very low recurrence rate.

• Radiation Therapy: Radiation therapy uses high-energy X-rays to kill cancer cells. It can be given after surgery to remove the tumor cells that remain from surgery.

• Targeted Therapy: Targeted therapy uses specialized drugs that target and kill cancer cells.

• Palliative Care: Palliative care in childhood cardiac tumors helps relieve symptoms and side effects of the disease and treatment.

Conclusion

Cardiac tumors in children are rare, and it is mostly benign. Benign childhood cardiac tumors often exhibit non-specific symptoms that make it difficult to diagnose the condition at an early stage. The symptoms are more specific and severe as it transforms into a malignant tumor. Treatment options may depend on the tumor type, stage, and severity. Surgery shows good and long-term outcomes in benign tumors. Chemotherapy and radiation therapy are most effective in treating malignant tumors. The prognosis of benign tumors is better than malignant tumors.